A diffusor for supplying of gases could have several range of use. For instance farming of aqua cultural organisms for instance fish. A diffusor for supplying gases could also be used in sewage treatment, supplying of oxygen in lakes but also other water treatment arrangement.
Aquaculture farming of food is a growing industry that is striving to satisfy a growing market for protein based food, such as fish. There are different methods for growing the protein based food, like outdoors in open ponds or net cage in seawater or fresh water, or indoor tanks.
The growth of the fish or protein based food must satisfy the conditions necessary to remain health and growth. For instance, the farmed organisms needs a continuous supply of clean water at correct temperature, sufficient oxygen and food.
Successful production depends on good oxygen management. The addition of oxygen in a pure form or as air is essential to sufficient growth, good feed conversion ratio and the survival at a low oxygen level will reduce growth, increase the susceptibility of the farmed organisms to diseases and parasites, and decrease production and profitability.
The addition of oxygen or air could also be used in the delousing of the fish.
Adding of oxygen or other gases is especially important in tanks where the density of the farmed organisms is high.
Other examples where supplying of gases to water are applied are sewage treatment of wastewater or supplying of oxygen in lakes or ponds. Wastewater treatment can be based upon chemical or biological treatment and both technologies are relevant for adding gases to achieve the desired results.
Publication WO03024578 discloses a device for use in aquaculture installations, which enables oxygen to be added in the form of micro-bubbles in large amounts, to seawater in open cage installations. The device comprising a perforated tube for oxygen supply and at least one perforated tube for oxygen distribution, the perforated tube for oxygen supply is arranged at the inside of the perforated tube for oxygen distribution.
A disadvantage of the known solution is that the arrangement is complex in that both tubes must be perforated to distribute the oxygen and that the space between the two perforated tubes are divided into chambers.
The perforated tube for oxygen supply could also clog over time and are difficult to clean. It is also necessary for the inner perforated tube to have lesser number of perforations than the outer perforated tube.
Contrary to beliefs, tests made by the applicant have shown that there is no need to supply the oxygen very evenly within the distribution tube.
The present invention is advantageous over the above prior art in that the tubes for oxygen supply arranged within the tube for oxygen distribution, is a tube without perforations and is therefore a simpler solution to distribute oxygen.
Other and further objects, features and advantages will appear from the following description of preferred embodiments of the invention, which are given for the purpose of description, and given in context with the appended drawings.